Statistics of Quasars Multiply Imaged by Galaxy Clusters

Abstract

We compute the expected number of quasars multiply imaged by cluster-size dark halos for current wide-field quasar surveys by carrying out a large ensemble of ray-tracing simulations through clusters from a cosmological N-body simulation of the ΛCDM cosmology, with power spectrum normalization σ8=0.95. Our calculation predicts ~4 quasar lenses with splittings θ>10'' in the SDSS spectroscopic quasar sample, consistent with the recent discovery of the wide separation lens SDSS J1004+4112, which has θ=14.6''. The SDSS faint photometric quasar survey will contain ~12 multiply imaged quasars with splittings θ>10''. Of these, ~2 will be lenses with θ>30'', and ~2 will be at high redshift (zs~4).